\begin{problem}{Droid formation}
{formation.in}{formation.out}
{2 seconds}{256 Mebibytes}

\epigraph{A long time ago (but somehow in the future),
 in a Galaxy Far Far Away\ldots}

--- Your majesty, Jedi detachment almost finished to mine our new
 Death Cube! New battle droids are unable to restrain them! What to do!?

--- Rest assured! What is the strength of every troop of droids?

--- 12 droids, your majesty!

--- Fools! I told you that a troop should have 4 variants of evolution
 but troop of 12 droids has 6! This perverts threads of the Power~--- and
 infeeds Jedis! Regroup the army~--- and Jedis will lose!

--- Yes sir!

Number of variants of evolution of a troop of droids is the number of ways to
draw it up in rows so that every row has the same number of droids. For
example, a troop of 12 droids can be arranged in 1 row of 12 droids, 2 rows of
6 droids, 3 rows of 4 droids, 4 rows of 3 droids, 6 rows of 2 droids and 12
rows consisting of 1 droid each. So, as the Emperor noticed, there are 6
variants of evolution for this troop of droids.

You problem is more general~--- given the number $K$ of favorable variants of
evolution, find the smallest positive size of a troop of droids $N$ which has
this very number of variants of evolution.

\InputFile

Input file contains only number $K$ from the problem
statement $(1 \le K \le 10^5)$.

\OutputFile

Write to the output file the required number $N$. If there is no such number,
write to the output file number 0 instead.

\Example

\begin{example}
\exmp{
4
}{
6
}%
\end{example}

\end{problem}
